1. Field of the Invention
This invention relates to a method of adjusting a fuel distribution, a membrane which adjusts a fuel distribution, a method of producing a membrane which adjusts a fuel distribution, a fuel cell, and a method of producing a fuel cell.
2. Background Art
With the advancement of electronics in recent years, electronic devices have become more downsized, more powerful, and more portable, requirement of downsizing and higher energy density for the cells used therein has become enhanced. Hence, middle-sized or downsized and lightweight fuel cells having high capacity has been emphasized. Direct Methanol Fuel Cell (DMFC) in which methanol serves as the fuel is more suitable for downsizing than a fuel cell using hydrogen gas because there is no difficulty in handling hydrogen gas and a device and such for producing hydrogen by reforming a liquid fuel is not required.
In the direct methanol fuel cell, a fuel electrode (anode electrode), an electrolyte membrane of solid, and an oxidant electrode (cathode electrode) are provided so as to be contiguous to one another in the order, and thereby, a membrane electrode assembly is formed. A fuel (methanol) is supplied to the fuel side and the fuel (methanol) is reacted by a catalyst in the vicinity of the electrolyte membrane to take out proton (H+) and electron (e−). Here, for improving electric characteristics of the fuel cell, a technique for uniformly supplying the fuel (methanol) to the fuel electrode side (see, Japanese unexamined Patent publication JP-A 2006-196430(Kokai), and German unexamined Patent publication No. 19853911).
However, in the technique disclosed in Japanese unexamined Patent publication JP-A 2006-196430(Kokai) and German unexamined Patent publication No. 19853911, a temperature distribution in the membrane electrode assembly is not considered. Therefore, the technique for uniformly supplying the fuel (methanol) to the fuel electrode side has had a problem of improvement of electric characteristics of the fuel cell, particularly, improvement of the power.